67P compared to other comets, asteroids and Earth objects. Even the Death Star. Illustration by Judy Schmidt.
We’ve seen a bunch of pictures comparing Comet 67P/Churyumov–Gerasimenko with all kinds of cities and objects on Earth, but it’s hard to put everything in perspective. Just how big is this thing? How big is it compared to other asteroids and comets we’ve imaged? What about more familiar objects, like the Burj Khalifa and Central Park?
How big is 67P/Churyumov–Gerasimenko compared to the Death Star?!?
Fortunately, our good friend Judy Schmidt@SpaceGeck took it upon herself to clear this all up. She created this wonderful infographic that shows 67/P surrounded by a bunch of other objects in the Solar System with a similar size. There’s Siding Spring, the Mars moon Deimos, 19P/Borrelly, 103P/Hartley, and others.
And then they’re compared to the Burj Khalifa, a blue whale, the Great Pyramid of Giza, and much more.
But most importantly, at the bottom of the image, you can see the slight curvature of a fully operational Death Star. Yeah… those things are pretty big.
Anyway, I highly recommend you check out Judy’s post about the illustration over on Flickr and read her behind the scenes commentary.
And while you’re at it, check out her previous illustration of 100 planetary nebulae in a single image.
Getting stuff into space is complicated and expensive. And what do you do when your fancy space gadget breaks. You print out a new one, of course, with your fancy space 3D printer. It turns out, space exploration is one of the best uses for this technology. Continue reading “Astronomy Cast Ep. 355: Maker Space: 3D Printing Exploration”
Everywhere we look on Earth, we find life. Even in the strangest corners of planet. What other places in the Universe might be habitable?
There’s life here on Earth, but what other places could there be life? This could be life that we might recognize, and maybe even life as we don’t understand it.
People always accuse me of being closed minded towards the search for life. Why do I always want there to be an energy source and liquid water? Why am I so hydrocentric? Scientists understand how life works here on Earth. Wherever we find liquid water, we find life: under glaciers, in your armpits, hydrothermal vents, in acidic water, up your nose, etc.
Water acts as a solvent, a place where atoms can be moved around and built into new structures by life forms. It makes sense to search for liquid water as it always seems to have life here. So where could we go searching for liquid water in the rest of the Universe?
Under the surface of Europa, there are deep oceans. They’re warmed by the gravitational interactions of Jupiter tidally flexing the surface of the moon. There could be life huddled around volcanic vents within its ocean. There’s a similar situation in Saturn’s Moon Enceladus, which is spewing out water ice into space; there might be vast reserves of liquid water underneath its surface. You could imagine a habitable moon orbiting a gas giant in another star system, or maybe you can just let George Lucas imagine it for you and fill it with Ewoks.
The white dwarf G29-38 (Image Credit: NASA)
Let’s look further afield. What about dying white dwarf stars? Even though their main sequence days are over, they’re still giving off a lot of energy, and will slowly cool down over the coming billions of years. Brown dwarfs could get in on this action as well. Even though they never had enough mass to ignite solar fusion, they’re still generating heat. This could provide a safe warm place for planets to harbor life.
It gets a little trickier in either of these systems. White and brown dwarfs would have very narrow habitable zones, maybe 1/100th the size of the one in our Solar System. And it might shift too quickly for life to get started or survive for very long. This is our view, what we know life to be with water as a solvent. But astrobiologists have found other liquids that might work well as solvents too.
Artist concept of Methane-Ethane lakes on Titan (Credit: Copyright 2008 Karl Kofoed). Click for larger version.
What about life forms that live in oceans of liquid methane on Titan, or creatures that use silicon or boron instead of carbon. It might just not be science fiction after all. It’s a vast Universe out there, stranger than we can imagine. Astronomers are looking for life wherever makes sense – wherever there’s liquid water. And if they don’t find any there, they’ll start looking places that don’t make sense.
What do you think? When we first find life, what will be its core building block? Silicon? Boron? or something even more exotic?
And if you like what you see, come check out our Patreon page and find out how you can get these videos early while helping us bring you more great content!
You could fit all the planets within the average distance to the Moon.
I ran into this intriguing infographic over on Reddit that claimed that you could fit all the planets of the Solar System within the average distance between the Earth and the Moon.
I’d honestly never heard this stat before, and it’s pretty amazing how well they tightly fit together.
But I thought it would be a good idea to doublecheck the math, just to be absolutely certain. I pulled my numbers from NASA’s Solar System Fact Sheets, and they’re a little different from the original infographic, but close enough that the comparison is still valid.
So what could we do with the rest of that distance? Well, we could obviously fit Pluto into that slot. It’s around 2,300 km across. Which leaves us about 2,092 km to play with. We could fit one more dwarf planet in there (not Eris though, too big).
The amazing Wolfram-Alpha can make this calculation for you automatically: total diameter of the planets. Although, this includes the diameter of Earth too.
We were witness to a once in a million year event. A close approach of Comet Siding Spring to the Planet Mars. And fortunately, humanity had a fleet of spacecraft orbiting the Red Planet, ready to capture this monumental event in real time. What did we see? What will we learn? Continue reading “Astronomy Cast Ep. 354: Mars vs Comet Siding Spring”
Since telescopes let us look back in time, shouldn’t we be able to see all the way back to the very beginning of time itself? To the moment of the Big Bang?
You’ve probably heard that looking out into space is like looking back in time. As it takes light 1 second to get from the Moon to us. Whenever we view it, we’re seeing it 1 second in the past. The Sun is 8 light minutes away, and the light we see from it is from 8 minutes into the past.
A better example might be Andromeda, it’s 2.5 million light years away… and you guessed it, we’re seeing it 2.5 million years in the past. Since the Big Bang happened 13.7 billion years ago, using this idea, shouldn’t we be able look all the way back to the beginning of time, even if we’ve misplaced the key to our Tardis?
At the very beginning of the Universe, seconds after the Big Bang, everything was mushed together. Energy and matter were the same thing. Dogs and cats lived together. There was no difference between light and radiation, it was all just one united force.
You couldn’t see it, because light didn’t actually exist. There were no such thing as photons.
However, if you’re still insisting there’s no such thing as photons, you might want to check yourself. After these things started to separate. Photons and particles became actual things. Electromagnetism and the weak nuclear force split off and formed new bands, but could never quite get the momentum of the original lineup.
By the end of the first second, neutrons and protons were around, and they were getting mashed by the intense heat and pressure into the first elements. But you still couldn’t see that because the whole Universe was like the inside of a star. Everything was opaque. It was Scarlett Johansson hot, and too crazy to form stable atoms with electrons as we see today.
Artist’s conception of Planck, a space observatory operated by the European Space Agency, and the cosmic microwave background. Credit: ESA and the Planck Collaboration – D. Ducros
After the Universe was about 380,000 years old, it had cooled down to the point that proper atoms could form. This is the moment when light could finally move, and travel distances across the Universe to you and get caught up in your light buckets. In fact, this light is known as the cosmic microwave background radiation.
So, how come we don’t see all this freed light in all directions with our eyes? It’s because the region of space where it exists is so far away, and travelling away from us so quickly. The light’s wavelengths have been stretched out to the point that light has been turned into microwaves. It’s only with sensitive radio telescopes and space missions that astronomers can even detect it.
Unfortunately, we’ll never be able to see the Big Bang. Even though we’re looking back in time, right to the edge of the observable Universe, it’s just beyond our reach. If you could look at the Universe at any point in time, what would it be? Tell us in the comments below.
And if you like what you see, come check out our Patreon page and find out how you can get these videos early while helping us bring you more great content!
Hi everyone, I just wanted to apologize for the problem with comments we were having for the last month, there’s was an issue with our upgrade to WordPress 4.0. There was an incompatibility with our Theme, and then were having problems upgrading to the next version of the theme without taking the site offline.
Anyway, we were finally able to fix the problem and upgrade WordPress, our Theme and make comments work again.
I apologize for the disruption.
Fraser Cain
Publisher
Universe Today
P.S. But now that there’s a new theme, expect some more design changes. 🙂
Soft drink sizes, SUV’s, baseball caps, hot dogs and truck nuts.
Astronomers mostly measure stars in terms of mass and use the Sun as a yard stick. This star is 3 solar masses, that star is 10 solar masses, and so on.
We’re pandering to those of you who want the most massive stuff as opposed to the most volumetric stuff. So if you want the biggest truck, but don’t care if it’s got the most truck atoms in one place, this might not be for you.
How massive can planets get, and where can I order a custom one more massive than a star?
It all depends on what your planet is made of. There are two flavors of planets, gas and rock.
Gas planets, like Saturn and Jupiter are pretty much made of the same stuff as our Sun.
Jupiter’s pretty big, but it’s actually only about 1/1000th the mass of our star. If you made it more massive. by crashing about 80 Jupiters together, you’d get the same amount of mass as the smallest possible red dwarf star.
And all that mass would compress and heat up the core and it would ignite as a star.
Artist’s View of Extrasolar Planet HD 189733b
Extrasolar planet astronomers have turned up some pretty massive gas planets. The most massive so far contains 28.7 times the mass of Jupiter.
That’s so massive it’s more like a brown dwarf.
But if you had a planet entirely made of rock, like the Earth. It would need to be much, much larger before its core would ignite in fusion.
It would need to be dozens of times the mass of our Sun.
Stars with 8-11 stellar masses can fuse silicon. So a rocky planet would need millions of times the mass of the Earth before it would have that kind of pressure and temperature.
So you could get a situation where you have more mass than the Sun in a rock flavored world, and it wouldn’t ignite as a star. It would get pretty warm though.
No star can burn iron. In fact, when stars develop iron in their core, that’s when they shut down suddenly and you get a supernova.
Feel free to collect all the iron in the Universe together and lump it into a ridiculously huge pile and no matter how long you stare at for, it’ll never boil or turn into a star.
It might turn into a black hole, though.
Artist’s impression of Kepler-10c (foreground planet)
The largest rocky planet ever discovered is Kepler 10c, with 17 times the mass of Earth.
Massive, but nowhere near the smallest star.
There’s new research that says that heavier elements blasted out of supernovae might collect within huge star forming nebulae, like gold in the eddies of a river. This metal could collect into actual stars. Perhaps 1 in 10,000 stars might be made of heavier elements, and not hydrogen and helium.
Metal stars.
So, it’s theoretically possible. There might be corners of the Universe where enough metal has collected together that you could end up with a star that’s made up of planety stuff. And that’s pretty amazing.
What do you think? If we found one of these giant metal stars, what should we call it?
And if you like what you see, come check out our Patreon page and find out how you can get these videos early while helping us bring you more great content!
